favoritism
n.the act of giving unfair support or better treatment to one person or group over others.
n.the practice of giving unfair preferential treatment to one person or group at the expense of another.
“The manager was accused of favoritism toward his friends.”
“Teachers must be careful to avoid any appearance of favoritism when grading the final projects of their students.”
“The company's promotion policy was designed to eliminate favoritism by requiring objective performance metrics rather than relying on personal recommendations from senior leadership.”
Often paired with the preposition 'toward' or 'towards'.
“So-called financial favouritism can cause jealousy and resentment long into adulthood.”
From favorite + -ism.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.